Stack object data structures do not
contain code to throw an exception when a stack.pop() function is called on an
empty stack. This is due to the fact that it is easy to establish this
exception handing elsewhere. Create a class named SafeStack that implements a
stack of strings.
Use an instance of stack from <string> to hold
string values and implement the same interface as the data type. However,
your implementation (class) should throw an exception if an attempt is
made to remove a value from an empty stack.